Aquarium Fish Database

Explore freshwater aquarium fish by care level, size, temperament, swimming zone, water parameters, and compatibility.

Beginner – Intermediate

Mimicry Otocinclus

Otocinclus mimulus

Adult size
up to 4.5 cm
Aquarium size
45 L or larger
Temperament
Peaceful
Zone
Bottom to middle swimmer
Temp
22–26 °C
Beginner – Intermediate

Mini Rosy Tetra

Hyphessobrycon dorsalis

Adult size
up to 3 cm
Aquarium size
30 L or larger
Temperament
Peaceful
Zone
Middle to top swimmer
Temp
23–28 °C
Beginner – Intermediate

Miniature Pencilfish

Nannostomus anduzei

Adult size
up to 2 cm
Aquarium size
30 L or larger
Temperament
Peaceful
Zone
Middle to top swimmer
Temp
22–28 °C
Intermediate

Mirabilis Eartheater

Geophagus mirabilis

Adult size
up to 20 cm
Aquarium size
240 L or larger
Temperament
Peaceful
Zone
Middle swimmer
Temp
22–30 °C
Beginner – Intermediate

Molly

Poecilia latipinna

Adult size
up to 12 cm
Aquarium size
100 L or larger
Temperament
Peaceful
Temp
22–26 °C
Beginner – Intermediate

Monica’s Tetra

Moenkhausia monicae

Adult size
up to 5 cm
Aquarium size
45 L or larger
Temperament
Peaceful
Zone
Middle to top swimmer
Temp
22–26 °C
Beginner – Intermediate

Monkey Goby

Neogobius fluviatilis

Adult size
up to 20 cm
Aquarium size
240 L or larger
Temperament
Peaceful
Zone
Bottom dweller
Temp
4–20 °C
Beginner – Intermediate

Montags Tetra

Hyphessbrycon montagi

Adult size
up to 3 cm
Aquarium size
30 L or larger
Temperament
Peaceful
Zone
Middle to top swimmer
Temp
22–27 °C
Beginner – Intermediate

Moonlight Gourami

Trichopodus microlepis

Adult size
up to 15 cm
Aquarium size
160 L or larger
Temperament
Peaceful
Zone
Middle to top swimmer
Temp
22–30 °C
Intermediate

Morse Knifefish

Gymnorhamphichthys hypostomus

Adult size
up to 21.5 cm
Aquarium size
300 L or larger
Temperament
Peaceful
Zone
Bottom to middle swimmer
Temp
25–28 °C
Intermediate – Advanced

Motoro Stingray

Potamotrygon motoro

Adult size
up to 90 cm
Aquarium size
900 L or larger
Temperament
Peaceful
Zone
Bottom dweller
Temp
24–26 °C
Beginner – Intermediate

Mottled Ctenopoma

Ctenopoma weeksii

Adult size
up to 12 cm
Aquarium size
120 L or larger
Temperament
Peaceful
Zone
Bottom to middle swimmer
Temp
23–27 °C
Beginner – Intermediate

Mountain Redbelly Dace

Chrosomus oreas

Adult size
up to 7 cm
Aquarium size
80 L or larger
Temperament
Peaceful
Zone
Middle to top swimmer
Temp
15–25 °C
Intermediate

Mousetail Knifefish

Gymnorhamphichthys rondoni

Adult size
up to 15 cm
Aquarium size
160 L or larger
Temperament
Peaceful
Zone
Bottom to middle swimmer
Temp
25–28 °C
Beginner

Moustached Danio

Danio dangila

Adult size
up to 12 cm
Aquarium size
120 L or larger
Temperament
Peaceful
Zone
Middle to top swimmer
Temp
16–24 °C
Beginner – Intermediate

Murray River Rainbowfish

Melanotaenia fluviatilis

Adult size
up to 10 cm
Aquarium size
120 L or larger
Temperament
Peaceful
Zone
Middle to top swimmer
Temp
20–25 °C
Beginner – Intermediate

Myer’s Hillstream Loach

Pseudogastromzon myersi

Adult size
up to 6 cm
Aquarium size
80 L or larger
Temperament
Peaceful
Zone
Bottom dweller
Temp
20–24 °C
Beginner – Intermediate

Napo Corydoras

Corydoras napoensis

Adult size
up to 5 cm
Aquarium size
60 L or larger
Temperament
Peaceful
Zone
Bottom dweller
Temp
22–26 °C
Beginner – Intermediate

Narayan Barb

Pethia setnai

Adult size
up to 7 cm
Aquarium size
80 L or larger
Temperament
Peaceful
Zone
Middle swimmer
Temp
20–26 °C
Beginner – Intermediate

Nego Dagua Tetra

Hyphessobrycon negodagua

Adult size
up to 3 cm
Aquarium size
30 L or larger
Temperament
Peaceful
Zone
Bottom to middle swimmer
Temp
23–27 °C
Intermediate

Neon Blue Rasbora

Sundadanio axelrodi

Adult size
up to 2 cm
Aquarium size
30 L or larger
Temperament
Peaceful
Zone
Middle to top swimmer
Temp
22–26 °C
Beginner – Intermediate

Neon Borneo Sucker

Gastromyzon lepidogaster

Adult size
up to 10 cm
Aquarium size
120 L or larger
Temperament
Peaceful
Zone
Bottom dweller
Temp
18–24 °C
Beginner – Intermediate

Neon Green Rasbora

Microdevario kubotai

Adult size
up to 2 cm
Aquarium size
30 L or larger
Temperament
Peaceful
Zone
Middle to top swimmer
Temp
22–27 °C
Beginner – Intermediate

Neon Red Rasbora

Sundadanio rubellus

Adult size
up to 2 cm
Aquarium size
30 L or larger
Temperament
Peaceful
Zone
Middle to top swimmer
Temp
22–26 °C
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